Condensed Consolidated Statements of Equity - USD ($) $ in Millions	Total		Common Stock	Additional Paid-In Capital	Common Stock Held in Treasury	Retained Earnings	Accumulated Other Comprehensive Loss, Net of Tax	Lear Corporation Stockholders' Equity	Non-controlling Interests	Redeemable Non-controlling Interests
Balance at beginning of period at Dec. 31, 2017	$ 4,292.6		$ 0.7	$ 1,215.4	$ (724.1)	$ 4,171.9	$ (513.4)	$ 4,150.5	$ 142.1
Comprehensive income (loss):
Net income	721.9					685.1		685.1	36.8
Other comprehensive income (loss)	(116.7)						(114.3)	(114.3)	(2.4)
Total comprehensive income (loss)	605.2					685.1	(114.3)	570.8	34.4
Stock-based compensation	27.1			27.1				27.1
Net issuance of shares held in treasury in settlement of stock-based compensation	(45.8)			(75.7)	29.9			(45.8)
Repurchase of shares of common stock	(295.7)				(295.7)			(295.7)
Dividends declared to Lear Corporation stockholders	(94.7)					(94.7)		(94.7)
Dividends declared to non-controlling interest holders	(59.6)								(59.6)	$ (4.7)
Affiliate transaction	14.0								14.0
Redeemable non-controlling interest adjustment	(14.6)					(14.6)		(14.6)
Acquisition of outstanding noncontrolling interest	(3.4)								(3.4)
Balance at end of period at Jun. 30, 2018	4,427.4		0.7	1,166.8	(989.9)	4,750.0	(627.7)	4,299.9	127.5
Balance at beginning of year at Dec. 31, 2017										153.4
Comprehensive income (loss):
Net income										7.3
Other comprehensive income (loss)										(3.1)
Total comprehensive income (loss)										4.2
Dividends declared to non-controlling interest holders	(59.6)								(59.6)	(4.7)
Redeemable noncontrolling interest adjustment										14.6
Balance at end of year at Jun. 30, 2018										167.5
Balance at beginning of period at Mar. 31, 2018	4,554.6		0.7	1,156.4	(851.7)	4,474.8	(380.8)	4,399.4	155.2
Comprehensive income (loss):
Net income	351.2					331.4		331.4	19.8
Other comprehensive income (loss)	(254.5)						(246.9)	(246.9)	(7.6)
Total comprehensive income (loss)	96.7					331.4	(246.9)	84.5	12.2
Stock-based compensation	13.9			13.9				13.9
Net issuance of shares held in treasury in settlement of stock-based compensation	(1.4)			(3.5)	2.1			(1.4)
Repurchase of shares of common stock	(140.3)				(140.3)			(140.3)
Dividends declared to Lear Corporation stockholders	(47.0)					(47.0)		(47.0)
Dividends declared to non-controlling interest holders	(39.9)								(39.9)	(4.7)
Redeemable non-controlling interest adjustment	(9.2)					(9.2)		(9.2)
Balance at end of period at Jun. 30, 2018	4,427.4		0.7	1,166.8	(989.9)	4,750.0	(627.7)	4,299.9	127.5
Balance at beginning of year at Mar. 31, 2018										170.3
Comprehensive income (loss):
Net income										3.8
Other comprehensive income (loss)										(11.1)
Total comprehensive income (loss)										(7.3)
Dividends declared to non-controlling interest holders	(39.9)								(39.9)	(4.7)
Redeemable noncontrolling interest adjustment										9.2
Balance at end of year at Jun. 30, 2018										167.5
Balance at beginning of period at Dec. 31, 2018	4,360.6		0.6	1,017.4	(225.1)	4,113.6	(705.8)	4,200.7	159.9
Comprehensive income (loss):
Net income	445.8					411.7		411.7	34.1
Other comprehensive income (loss)	8.1						7.6	7.6	0.5
Total comprehensive income (loss)	453.9					411.7	7.6	419.3	34.6
Stock-based compensation	14.3			14.3				14.3
Net issuance of shares held in treasury in settlement of stock-based compensation	(29.6)			(66.4)	38.0	(1.2)		(29.6)
Repurchase of shares of common stock	(279.5)				(279.5)			(279.5)
Dividends declared to Lear Corporation stockholders	(94.6)					(94.6)		(94.6)
Dividends declared to non-controlling interest holders	(31.2)								(31.2)
Redeemable non-controlling interest adjustment	5.8					5.8		5.8
Acquisition of outstanding noncontrolling interest	(0.2)								(0.2)
Balance at end of period at Jun. 29, 2019	4,399.5	[1]	0.6	965.3	(466.6)	4,435.3	(698.2)	4,236.4	163.1
Balance at beginning of year at Dec. 31, 2018	158.1									158.1
Comprehensive income (loss):
Net income										2.3
Other comprehensive income (loss)										0.4
Total comprehensive income (loss)										2.7
Dividends declared to non-controlling interest holders	(31.2)								(31.2)
Redeemable noncontrolling interest adjustment										(5.8)
Balance at end of year at Jun. 29, 2019	155.0	[1]								155.0
Balance at beginning of period at Mar. 30, 2019	4,393.7		0.6	961.5	(305.6)	4,300.3	(711.5)	4,245.3	148.4
Comprehensive income (loss):
Net income	200.9					182.8		182.8	18.1
Other comprehensive income (loss)	10.0						13.3	13.3	(3.3)
Total comprehensive income (loss)	210.9					182.8	13.3	196.1	14.8
Stock-based compensation	4.8			4.8				4.8
Net issuance of shares held in treasury in settlement of stock-based compensation	(0.4)			(1.0)	0.6			(0.4)
Repurchase of shares of common stock	(161.6)				(161.6)			(161.6)
Dividends declared to Lear Corporation stockholders	(46.9)					(46.9)		(46.9)
Dividends declared to non-controlling interest holders	0.1								0.1
Redeemable non-controlling interest adjustment	(0.9)					(0.9)		(0.9)
Acquisition of outstanding noncontrolling interest	(0.2)								(0.2)
Balance at end of period at Jun. 29, 2019	4,399.5	[1]	$ 0.6	$ 965.3	$ (466.6)	$ 4,435.3	$ (698.2)	$ 4,236.4	163.1
Balance at beginning of year at Mar. 30, 2019										156.6
Comprehensive income (loss):
Net income										1.1
Other comprehensive income (loss)										(3.6)
Total comprehensive income (loss)										(2.5)
Dividends declared to non-controlling interest holders	0.1								$ 0.1
Redeemable noncontrolling interest adjustment										0.9
Balance at end of year at Jun. 29, 2019	$ 155.0	[1]								$ 155.0

[1] Unaudited.